Image credit: LIGO/Axel Mellinger

The approximate location of the gravitational-wave event detected on December 26, 2015 by LIGO is shown on this sky map of the southern hemisphere. The colored lines represent different probabilities for where the signal originated: the outer purple line defines the region where the signal is predicted to have come from with a 90 percent confidence level; the inner yellow line defines the target region at a 10 percent confidence level.